The main aim of the project is the implementation and evaluation of a stepped care model (SCM) for patients with depression with 6 treatment options of varying intensity and setting, including innovative technologies (e-mental health, telephone-based psychotherapy). Within this complex intervention, patients are treated by a multiprofessional network of health care providers in Hamburg, Germany. The study compares the SCM condition (intervention group) to a control group receiving treatment as usual (cluster randomization on the level of participating general practitioners). It is expected that the SCM condition will show better results regarding reduction of mental symptoms, improvement of quality of life, more efficient access to care and better cost-benefit ratio.